Irrigation and Rootstock Effects on the Phenolic Concentration and Aroma Potential of Vitis vinifera L. cv. Cabernet Sauvignon Grapes

Abstract

Compositional changes of skin and seed phenolic compounds and berry glycosylated aroma precursors were measured in Vitis vinifera L. cv. Cabernet Sauvignon onto 1103P and SO4 rootstocks, in three irrigation regimes (FI, 100% of evapotranspiration; DI, 50% of evapotranspiration; and NI, non-irrigated). The study was conducted in a commercial vineyard of central Greece, in a factorial experiment during two growing seasons (2005-2006). Grape samples were obtained at commercial harvest. The deficit water supply decreased berry size but did not affect the skin/pulp weight ratio. Water limitation, especially pre-veraison, caused a substantial increase of skin anthocyanin concentration, and this effect was independent of water deficit-induced reductions in berry size and vine vigor. Among individual anthocyanins, malvidin-3-O-glucoside was mostly affected by water supply. The rootstock genotype did not affect berry growth parameters and skin polyphenol concentrations. The irrigation regime (mainly post-veraison) and rootstock genotype affected total flavan-3-ol monomers in seed tissue, mainly as a result of variations in the catechin amount. The lower seed phenolic concentration was found in non-irrigated and SO4-grafted vines, probably as a result of the restriction of scion vigor caused by these treatments, thereby altering cluster exposure. Skin and seed tannins were not affected by either rootstock or irrigation. The limited water supply was associated with increased aroma potential at harvest.

Irrigation and Leaf Removal Effects on Polyphenolic Content of Grapes and Wines Produced from cv. ‘Agiorgitiko’ (<i>Vitis vinifera</i> L.)

“…According to Kotseridis et al (2012) when leaf removal was applied before bloom, it had no effect on berry size in the case of 'Merlot' and 'Sangiovese' grapes, but reduced it in the case of 'Cabernet Sauvignon' grapes, leading to conclude that the effect may be cultivar-related. Irrigation had no effect on berry size, in contrast with studies showing that irrigation increases berry weight at harvest (Koundouras et al, 2009). Moreover, Kyraleou et al (2016a) observed a significant trend towards smaller berries in non-irrigated vines when compared with the full-irrigated ones.…”

“…Koundouras et al (2009) found that water limitation, especially pre-veraison, notably increased anthocyanin concentration in skin, affecting biosynthesis directly, with the greater effect on malvidin 3-O-monoglucoside (Mlv).…”

“…However, studies have often shown contradictory effects of water on berry components, mainly because of different irrigation volumes, period of water application and environmental conditions, leading to variations in water availability (Koundouras et al, 2009). Studies have shown that severe water deficit that usually occurs under semiarid conditions could be detrimental to fruit quality because of inadequate leaf area to ripen fruit or excessive grape exposure to sunlight leading to lower pigmentation in grapes as a result of increased berry temperature (Price et al, 1995).…”

Ecophysiological, Genetic, and Molecular Causes of Variation in Grape Berry Weight and Composition: A Review

“…One study reported that a reduction of vine vigor increased anthocyanin accumulation, but variations of composition were not clear regarding year and site (Cortell et al 2007a). Koundouras et al (2009) observed a higher concentration of malvidin-3-O-glucoside and malvidin-3-Ocoumarate glucoside for Cabernet Sauvignon vines grafted onto the high-vigor rootstock 1103P than those grafted on SO4. In most cases, it is uncertain whether the vigor affects directly the biosynthetic pathway through carbon availability or has an indirect effect via changes in canopy architecture and light and thermal microclimate (Downey et al 2006.…”

“…High temperatures are mainly reported to increase the proportion of acetylated to nonacetylated forms (Downey et al 2006, Spayd et al 2002, Tarara et al 2008). Water deficit results in an increase in anthocyanin concentration and the proportion of trihydroxylated anthocyanins as malvidin and p-coumaroylated derivatives (Castellarin and Gaspero 2007, Koundouras et al 2009, Ollé et al 2011.…”